Recently, hot-melt type adhesives have been widely used in view of improvement of environmental pollution and working environment. As a polymer for use in the hot-melt type adhesives, a styrene-based block copolymer is widely used.
Patent Literatures 1 and 2 propose adhesive compositions using a triblock copolymer and a diblock copolymer as a styrene-based block copolymer.
Patent Literature 3 proposes adhesive compositions using styrene-based block copolymers different in hydrogenation ratio, and discloses adhesive compositions containing a hydrogenated styrene-based block copolymer having a vinyl aromatic monomer content of 0 mass % or 20 mass % or more, a tackifier and an oil in different mixing ratios, in Examples and Comparative Examples thereof.
An adhesive composition to be used in an adhesive tape is required to have a balance between properties such as high ball tack, high tack strength, high retentivity, high coating property, color fastness, high runoff resistance from the edge of a laminate.